Interfacial tensions in healthy and atherosclerotic rabbit aortae. Higher values and lesion surfaces

Interfacial tensions at the saline/arterial wall interface were determined by measuring contact angles between various test fluid droplets and the walls of rabbit aortae immersed in physiological saline. These contact angles and the interfacial tensions of the test fluid/bathing fluid interface (measured by the Du Noüy ring method) were converted to saline/arterial wall interfacial tensions by applying Neumann's equation of state. Four diseased animals, fed an atherogenic diet for 6-8 weeks and 6 controls formed the experimental group. A significantly higher interfacial tension (P < 0.001), was determined for lesion surfaces in atherosclerotic arteries (0.36 +/- 0.08 (SEM) mM . M-1, n = 13) compared to both the surrounding undisturbed regions (0.035 +/- 0.01 mN . m-1, n = 14) and the intact surface of control vessels (0.060 +/- mN . m-1, n = 48). This increase may reflect a change in the strength of hydrophilic interactions associated with the lesion surface in atherogenesis.